//9.9
public class RegularPolygon {
    private int n=3;
    private double side = 1;
    private double x=0;
    private double y=0;
    public RegularPolygon(){
    }
    public RegularPolygon(int n,double side){
        this.n=n;
        this.side=side;
    }
    public RegularPolygon(int n , double size,double x ,double y){
        this.n=n;
        this.side=side;
        this.x=x;
        this.y=y;
    }
    public int GetN(){
        return n;
    }
    public void SetN(int n){
        this.n=n;
    }
    public double GetSide(){
        return side;
    }
    public void SetSide(double side){
        this.side=side;
    }
    public double GetX(){
        return x;
    }
    public void SetX(double x){
        this.x=x;
    }
    public double GetY(){
        return y;
    }
    public void SetY(double y){
        this.y=y;
    }
    public double GetPerimeter(){
        return n*side;
    }

    public double GetArea(){
        double ans=(n*side*side)/(4*Math.tan(Math.PI/n));
        return ans;
    }
}
